APPLIED CATALYSIS A-GENERAL
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2022
·
IF 5.723
Xiang Li,Xiaomin Ren,Maodi Wang,Qihua Yang
Direct hydrogenation of nitrobenzene (NB) to dicyclohexylamine (DCHA) is a green but challenging process due to the competition of cross-coupling reaction (to DCHA) and hydrogenation reaction (to byproduct). Herein, we report that the cross-coupling reaction to desired DCHA is greatly enhanced by tuning the acidity of supported Pd catalysts. It was found that Pd NPs loading on commercial γ-Al 2 O 3 (γ-Al 2 O 3-Com ) with moderate acidity were more selective than those on neutral SBA-15 or strongly acidic γ-Al 2 O 3 nanorods . The presence of acid site could promote the coupling reaction. By analyzing the correlation between hydrogenation activity and DCHA selectivity, it was found that the matched rate of hydrogenation and cross-coupling is the key factor to achieve high selectivity. This study may open a new avenue for the hydrogenation of nitroarenes to DCHA by regulating the acidity of supports and the reaction conditions.
研究领域:
化学工程
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催化
·
有机化学
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DOI
高影响因子
ACS ES&T Water
·
2026
·
IF 4.5
Chenglin Liu,Zhong Zhang,Siyuan Xiong,Sheng Wan,Zeyu Chen,Yao Cheng,Bintian Zhang,Xin Yang,Guomao Zheng
Identification of disinfection byproducts (DBPs) precursors remains a longstanding challenge due to the complexity of contaminated source water. Tire wear particles (TWPs) can be an overlooked source of DBPs precursors. To figure out the specific amine additives in tire rubber serving as potential nitrosamine precursors during chlorination, six frequently measured tire-derived amine additives, including N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD), N-isopropyl-N′-phenyl-p-phenylenediamine (IPPD), N-cyclohexyl-N′-phenyl-p-phenylenediamine (CPPD), N,N′-dicyclohexylurea (DCU), diphenylamine (DPhA), and N,N′-dicyclohexylamine (DCHA), were selected to simulate their degradation processes, and their DBPs formation potentials were evaluated under various water matrices. IPPD was found to have a high molar yield of N-nitrosodimethylamine (NDMA, up to 8%), while 6PPD exhibited a lower molar yield (∼0.1%) with the molar ratio of chlorine-to-ammonium nitrogen (Cl2:N = 2) and disinfectant-to-precursor (D/P = 10). Suspect and target screening approaches were further applied to identify the transformation products of IPPD, and the formation pathway of NDMA via IPPD was proposed. Furthermore, we assessed NDMA formation from IPPD in simulated TWP leachates through chlorination experiments in the presence of ammonia, which revealed that IPPD contributed up to 24% of the total NDMA formed. This study offers new insights into the previously overlooked source of nitrosamines from tire-derived amine additives.
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产品关联
DOI
高影响因子
American Journal of Translational Research
·
2019
·
IF 3.266
Zhongyue Huang,Huijie Gu,Xiaofan Yin,Long Gao,Kunxi Zhang,Yiming Zhang,Jun Xu,Liang Wu,Jingbo Yin,Lei Cui
Microspheres have gained immense popularity in bone tissue engineering because of their unique properties as injectable scaffolds for bone tissue regeneration. Herein, we evaluated the feasibility of using poly (γ-benzyl-L-glutamate) (PBLG) microspheres for bone engineering by examining the attachment, proliferation, and osteogenic differentiation of adipose-derived stem cells (ASCs) in vitro and the use of PBLG microspheres in healing non-union in vivo . Scanning electron microscopy and fluorescent 3, 30-dioctadecyloxacarbocyanine perchlorate-labeling were performed to study the attachment and growth of ASCs to the PBLG microspheres, and a DNA assay was performed to quantify cell proliferation with time. Osteogenic differentiation of ASCs cultured on the PBLG microspheres was assessed by determining alkaline phosphatase expression and extracellular calcium deposition, which was further confirmed by real-time polymerase chain reaction for osteogenesis-related genes. Femoral non-union were created in mouse models and filled with ASCs/PBLG microspheres in vivo . The results showed that ASCs attached, spread, and showed good osteogenic differentiation on the PBLG microspheres in vitro . Moreover, the ASCs/PBLG microspheres could repair the mouse femoral non-union in vivo . Thus, PBLG microspheres have good biocompatibility and cytocompatibility and are potentially useful as an injectable scaffolds for bone tissue engineering.
研究领域:
生物材料学
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骨组织工程
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再生医学
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产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 25
·10621-10627
·
IF 3.288
Xue Xiong,Meiling Qi
This work presents a novel column fabrication approach for capillary gas chromatography (CGC) through the condensation reaction of a hydroxyl-terminated polymer with a cross-linker inside a capillary column. In this work, polypropylene glycol (PPG 4000) and tris[3-(trimethoxysilyl)propyl]isocyanurate (ICS) were employed to fabricate the PPG-gel capillary column for GC analyses. Inside the column, a 3D cross-linked organogel network forms on the capillary inner surface by condensation of PPG 4000 with ICS under the given mild conditions. As a result, the PPG-gel column exhibited moderate polarity and showed distinctly advantageous resolving performance and inertness for carboxylic acids over the PPG column by the conventional static coating method. Also, it achieved high-resolution separations of the isomer mixtures of alkanes, alkylbenzenes and halobenzenes. Moreover, the PPG-gel column exhibited dramatically improved solvent stability because of its cross-linked organogel network. The organogel column displayed excellent column repeatability and reproducibility with the RSD% values in the range of 0.01–0.04% for run-to-run, 0.71–0.84% for day-to-day and 2.4–3.1% for column-to-column. The proposed organogel approach is facile and applicable to other analogous materials and has a promising future for wide applications.
研究领域:
分析化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2019
·
IF 3.858
Xue Xiong,Meiling Qi
This work presents the investigation of utilizing adenine-functionalized polypropylene glycol (APPG) for capillary gas chromatographic separations. The statically coated APPG column (0.25 mm i.d.) showed moderate polarity and high column efficiencies of 4660 plates/m and 4376 plates/m determined by n -octanol and naphthalene, respectively. Remarkably, the APPG column baseline resolved all the components of the Grob test mixture and displayed good peak shapes for some stringent analytes that are prone to peak tailing or severe adsorption. Also, it achieved complete separation of dimethylaniline isomers, which are difficult to be resolved due to their high resemblance in structures and properties. The above results demonstrate the high selectivity and inertness of the APPG column and its distinct advantages over the polypropylene glycol (PPG) column and commercial polyethylene glycol (PEG) column. In addition, its separation performance has good repeatability with the RSD values on retention times below 0.05% for run-to-run, 0.11–0.12% for day-to-day and 1.7–1.9% for column-to-column, respectively. Further, the APPG column was applied to determination of isomer impurities in commercial dimethylaniline products and to determination of the additives of anilines and phenols in a hair-dye product, proving its great potential for practical GC analysis.
研究领域:
分析化学
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色谱技术
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2022
·
IF 4.601
Ruijuan Duan,Meiling Qi
This work presents the investigation of two new pentiptycene (PP)-functionalized triblock copolymers (PEPE1, PEPE2) for gas chromatographic (GC) analyses with an aim to address the separation problems toward analytes of high resemblance in properties and a wide variety of components in complex samples. Up to date, these two materials are not reported in any fields. The PEPE1 and PEPE2 columns showed close column efficiency (above 4000 plates/m) but differed in polarity, morphology and separation performance. As testified by the challenging Grob test mixture, the PEPE1 column exhibited comprehensively higher separation capability than the PEPE2 column and the commercial reference columns. Also, the PEPE1 column achieved high-resolution performance for both apolar and polar isomers of high resemblance, such as xylenes, phenols and anilines. Moreover, it displayed high inertness towards carboxylic acids and excellent separation repeatability and reproducibility tested by the aniline isomers with the RSD values in the range of 0.01–0.04% for run-to-run, 0.09–0.13% for day-to-day and 1.2–2.0% for column-to-column, respectively. Its application to GC–MS analysis of the essential oil from tea flowers demonstrated its advantageous separation performance towards a wide range of components and proved its feasibility for practical analyses of complex samples.
研究领域:
化学
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分析化学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2014
·Vol. 3
·期 6
·1020-1031
·
IF 0
Jianjun Fang,Qi Yong,Kunxi Zhang,Wentao Sun,Shifeng Yan,Lei Cui,Jingbo Yin
In search of an injectable cellular delivery vehicle for tissue regeneration, porous microspheres fabricated from the synthetic polypeptide of poly(γ-benzyl-L-glutamate) (PBLG) were developed. The structural and morphological characteristics of the microspheres could be adjusted by changing the amounts of the gelatin porogen. PBLG microspheres fabricated from 6.5% gelatin content exhibited an average pore diameter of 50.9 ± 10.3 μm and a porosity of 86.58 ± 2.37%. Degradation in vitro of the microspheres could be well controlled by adjusting the molecular weight of PBLG, and the degradability in vivo showed a satisfactory degradation time range from 8 to 12 weeks. Articular chondrocytes, which were seeded within the PBLG porous microspheres, exhibited progressive proliferation and deposition of the cartilaginous extracellular matrix. After cultivation for 2 days in vitro, the PBLG porous microspheres loaded with chondrocytes were injected subcutaneously into nude mice. At 4, 8 and 12 weeks post-injection, neo-generated tissue was harvested for histological observations, which showed a typical cartilage structure and cartilaginous matrix accumulation. A gradual increase of GAG and COL II content in neo-generated tissue was detected by biochemical analysis. These results indicate that the fabricated porous microspheres showing controllable degradation properties, good biocompatibility and cytocompatibility are potentially useful as an injectable vehicle for cartilage tissue engineering.
研究领域:
组织工程
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生物材料
·
再生医学
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产品关联
DOI
PubMed
Reaction Chemistry & Engineering
·
2022
·Vol. 8
·期 3
·645-655
·
IF 5.2
Zhenhua Tian,Jianzhong Ma,Qiwu Liu,Hui Zhang
Amphoteric acrylic polymers are some of the commonly used leather retanning agents, and possess assistant-dyeing function in contrast to traditional anionic acrylic retanning agents. To further enhance the cationic modification degree of anionic acrylic retanning agents, various amines (dimethylamine, diethylamine, dipropylamine, diethanolamine, dicyclohexylamine and diphenylamine) with different structural characteristics were selected as raw materials to prepare amphoteric acrylic retanning agents via the Mannich reaction. Then, the obtained amphoteric acrylic retanning agents were used in leather-making, and the retanning and assistant-dyeing properties were investigated. Compared with the anionic acrylic retanning agents, all amphoteric acrylic retanning agents have better assistant-dyeing owing to the presence of amino groups. The retanning agents modified by different amines exhibit different properties. The amination degree of the acrylic polymer retanning agent modified by diethanolamine was the highest (40.8%) and had better assistant-dyeing, which was confirmed by its highest dye-uptake (87.5%) and K/S value (17.0). The tensile strength of leather retanned with diphenylamine-modified acrylic polymer was the highest (23.6 MPa). The thickening rate of the leather retanned with dipropylamine-modified acrylic polymer was the highest (23.8%). Considering these properties, the overall performance of the amphoteric acrylic polymer modified by diethanolamine was found to be the best.
研究领域:
制革化学
·
高分子化学
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产品关联
DOI
高影响因子
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